Tony DiTerlizzi is no stranger to stumbling into fantastical worlds — as a writer and artist he co-created “The Spiderwick Chronicles” and created the “WondLa” trilogy of children’s books (the final book, “The Battle for WondLa” was released earlier this month). But when he got the call to write a children’s book retelling the original “Star Wars” trilogy, to be illustrated with Ralph McQuarrie’s original concept drawings, he found himself entering a real-life magical realm: Lucasfilm.

“I visited the Lucasfilm archive at the Skywalker Ranch,” DiTerlizzi said during a recent event at Children’s Hospital Los Angeles benefiting his favorite charity, Starlight Children’s Foundation. “I thought it would be a room with a bunch of flat files of art. No, the Death Star was there. R2-D2 was there. There was the lost Ark of the Covenant. Indy’s hat. Willow. Ten-year-old Tony’s mind exploded. This is what happens when you’re a good nerd and you die — it’s heaven.”

Author and illustrator Tony DiTerlizzi. (Angela DiTerlizzi)

“The Adventures of Luke Skywalker, Jedi Knight,” to be released in October, is the first in a series of “Star Wars” children’s books to be released in the run-up to J.J. Abrams’ “Star Wars Episode VII,” which arrives in theaters Dec. 18, 2015. But what makes “The Adventures of Luke Skywalker” unique is the unusual collaboration between DiTerlizzi and McQuarrie, who died in 2012.

McQuarrie is beloved by “Star Wars” fans as the artist whose concept pieces played a pivotal role in creating the look of the films, from Darth Vader’s imposing mask in “A New Hope” to the speeder bikes on the forest moon of Endor in “Return of the Jedi.” (Click through the images above for a more detailed look at McQuarrie’s art.)

But because McQuarrie’s drawings and paintings were made ahead of the actual filming and because he didn’t always draw every iconic scene, DiTerlizzi had a challenge.

“He never painted either of the Death Stars blowing up, he never painted Obi-Wan and Darth Vader fighting with light sabers,” DiTerlizzi said.

So in planning, he had to decide which parts of the story would be focused on the text and which would rely on the art.

“That’s how a picture book is constructed,” he said. “It’s a symbiotic relationship.… But we had many conversations about how to handle the art. For instance, in the climax of Luke’s battle with Darth Vader, McQuarrie painted Luke with both hands. Do we tweak that in Photoshop?”

The decision was made not to change any of McQuarrie’s original drawings, which led to DiTerlizzi having to come up with some careful wording in order to tell the story the way fans know it, without contradicting the illustrations.

“I wrote something to the effect of ‘Darth Vader not only hurt Luke with his light saber, he hurt him with his words — the truth.'” DiTerlizzi said. “It’s not false. But it’s a little more poetic about how you go about it.”

Like so many of his generation, DiTerlizzi first saw “Star Wars” when he was 8 years old and was “blown away.” But it wasn’t until he was in middle school that he saved his allowance and bought the tie-in books featuring McQuarrie’s original drawings. He drew and re-drew the illustrations over and over as he was learning his own style in his adolescence.

Upon McQuarrie’s death in 2012, DiTerlizzi told Hero Complex the relationship between Lucas and McQuarrie was like the Beatles and their producer, George Martin. “You kind of needed both of them,” he said.

When he was asked to write the book by Disney Publishing, he expected to receive roughly 20 drawings to work from, but was in fact sent more than 200 of McQuarrie’s original works, some of which he’d never seen before. He also sought out the original screenplays to determine the exact words George Lucas used to describe the people, places and things that populated his galaxy.

While DiTerlizzi needed to simplify the story in order to craft a clean and concise children’s book, he also tried to bring out elements of the stories that may have been pushed aside over the years in favor of the more iconic moments.

For example, though McQuarrie never painted a scene for the moment in “Jedi” when Yoda and Obi-Wan Kenobi confirm that Darth Vader is Luke’s father and Leia is his sister, he did paint a cover for the influential 1978 “Star Wars” tie-in novel, “Splinter of the Mind’s Eye” featuring Darth Vader, Luke and Leia in a dramatic stance in a wooded environment.

“It perfectly illustrated the moment,” DiTerlizzi said. “If you’re 8 years old reading the story, you will have no idea. But if you’re a longtime fan, you’ll say, ‘Oh cool, ‘Splinter of the Mind’s Eye!'”

DiTerlizzi sees the book as a unique way to enter into the world of Lucas’ imagination, free of the distractions of modern moviemaking.

“This is going back to a time before the models and special effects,” he said. “It’s just one person writing out a story and someone with a paintbrush painting visions from that story.”